Fluid pressure underwater breathing apparatus



Dec. 10, 1957 G. K. MERCER 2,815,759

FLUID PRESSURE UNDERWATER BREATHING APPARATUS Filed March 22, 1955 3 Sheets-Sheet 1 Dec. 10, 1957 G. K. MERCER 2,815,750

. FLUID PRESSURE UNDERWATER BREATHING APPARATUS FiledIarch 22, 1955 V 3 Sheets-Sheet 2 Dec. 10, 1957 e. K. MERCER 2,815,750

' FLUID PRESSURE UNDERWATER BREATHING APPARATUS Fild llarch 22, '1955 a Sheets-Sheet 5 United States Patent FLUID PRESSURE UNDERWATER APPARATUS v Application March 22, 1955, Serial No. 495,994 7 Claims. Cl. 128-142) BREATHING This invention relates to fluid pressure apparatus, particularly underwater breathing apparatus.

Underwater breathing apparatus comprising compressed air bottles, a breathing connection comprising a face-mask or mouthpiece and means connecting said bottles and breathing connection to enable a diver to respirate, is shown. A demand valve of the type described in our co-pending application number Ser. No. 463,233, filed Oct. 19, 1954 may be provided between the breathing connection and air bottle to control the air flow and pressure in accordance with the depth at which the diver is working and in accordance, also, with his respiratory requirements.

Myinvention provides visual means to indicate to the diver when the pressure in his compressed air bottles falls below a predetermined value and also provides a combined reducing valve, excess pressure relief valve and on-off cock. 2

According to my invention the breathing apparatus comprises a gas bottle, a breathing connection, means connecting said bottle to said breathing connection, and means, operative only when the pressure in said bottle falls below a predetermined value, for indicatnig that the bottle requires replenishing.

Preferably the indicating means are visual. Where the breathing apparatus is an underwater apparatus said indicating means may comprise a stream of air bubbles arising' from a nozzle immediately infront of the divers eyes. The nozzle is operatively connected to a pressure indicating valve comprising a plunger forced into a valve seating position when the pressure in said bottle exceeds a predetermined value and spring-urged into a valve opening position, to allow a restricted flow of air to said nozzle, when the pressure in the bottle falls below said value. Visual means other than a stream of bubbles may be used. 1

The invention also comprises an improved combined reducing valve, excess pressure relief valveand on-off cock.

The invention will now be described with reference to the accompanying drawings of which:

Figure 1 is a sectional view of a part of a breathing apparatus constructed according to the invention.

Figure 2 is a sectional view of part of the apparatus of' Figure 1 taken on the line A-A and looking in the direction of the arrows.

Figure 3 is a view of a preferred indicating means.

In the embodiment illustrated in Figures 1 and 2a divers breathing apparatus incorporates a preferred visual indicating means and a combined reducing valve, relief valve and on-oif cock adapted to be connected as shown to a pair of compressed air bottles, 1, 2, mounted side by side on a container to be strapped to a divers back. The neck of each bottle is fluid-tightly secured to a manifold which extends between and interconnects said bottles 1, 2. A conventional charging nozzle (not shown) is provided. t

The manifold comprises a cylindrical member 3 having 2,815,750 Patented Dec. 10, 1957 ice a boss at each end, to which a bottle is secured. A conduit 4, extending axially within one wall of said cylindrical member 3, is connected at one end to one boss 5, which is hollow and communicates with the interior of the bottle 2 and at the other end to a passage 6 leading through the other boss 7 to the other bottle 1. This passage 6 also communicates with the interior of the cylindrical member 3, adjacent one end thereof.

Said end is provided with a closure member 8 having an air passage 9 extending therethrough to lead to a demand valve, e. g. of the type described in our co-pending application Ser. No. 463,233, filed Oct. 19, 1954. The cylindrical member 3 is provided, between its ends, with an inwardly-extending annular shoulder 10. Abutting one side of said shoulder 10 is an annular disc 11 having a sleeve 12 extending axially from the inner periphery thereof and towards the closure member 8. The sleeve 12 is provided, adjacent the annular disc 11, with a plurality of radially-extending holes 13. Slidable over said sleeve is a tubular valve member 14, comprising an inlet valve, having one end 15 chamfered to seat on a resilient seating washer 16 fitted against said annular disc 11. The other end of said valve member 14 has an outside diameter equal to the inside diameter of the other end of said member and is fluid-tightly slidable in a passage 17, leading to said passage 9, in said closure member 8. A helically wound return spring 18 is fitted between. said valve member 14 and the end of the passage 17.. The annular chamber 19 formed between the inlet valve: member 14 and the cylindrical member 3 comprises a high pressure chamber connected by said passage 6 and conduit 4 to the air bottles 1, 2. The step 20 on the inlet valve 14 caused by the reduction in diameter thereof is of the same radial width as the chamfered end 15. The inlet valve is thus balanced.

An annular piston 21 is fluid-tightly slidable in the cylinder member 3 on the other side of said shoulder 10, and the piston 21 has a tubular stem 22 extending therefrom through the sleeve 12 and the end of said stem 22 abuts the interior face of the step 20 of the inlet valve 14. The side of the annular piston 21 remote from the tubular stem 22 is formed as a relief valve seat 23, the.

' effective diameter of said seat 23 being smaller than the outside diameter of the annular piston 21. An abutment 24 on said piston 21 is adapted to contact a stop 25 in the cylindrical member 3 to restrict the movement thereof. The tubular stem 22 is provided with radially-extending holes 26 communicating with the holes 13 in the sleeve 12. This side of the annular shoulder 10 is con nected to atmosphere through port 27 and a liner 28 fitted in said cylindrical member 3 has a plunger 29 slidable therein, one end of said plunger 29 being provided with a relief valve closure member 30 to seat on the relief a valve seat 23. The end of the plunger 29 remote from the relief valve is provided with an axially-extending skirt 31 and one end of a control rod 32 is slidable Within said skirt 31. A light helical spring 33 is fitted between the plunger 29 and the adjacent end of the control rod 32. Two spring guides 34, 35 are slidably fitted on said control. rod 32, one thereof being adapted to abut the skirted end of the plunger 29 and the other being adapted to contact an abutment secured to said control rod 32. A main return spring 36 is fitted between said spring guides 34, 35-. The end of the control rod 32 remote from the relief valve is threaded and extends fluid-tightly through a closure member 37 fitted to the end of the cylindrical member 3 remote from the inlet valve 14; The extremity of said rod 32 projects exterior of said member 3 and is squared and a serrated hand-knob 38 is fitted thereto.

The boss 7 of the manifold provided with'thepassage 6 connecting the associated bottle 1 with the high pressure chamber 19 is likewise provided, substantially centrally, with an axially-extending passage 39 and the bottom of said passage 39 communicates, through an annular valve seat 40, withthe' passage 17 in the adjacentclosure member 8. A plug-41 is fluid-tightly fitted to the open. end of said passage 39 and a plunger 42 is fluidtightly. slidable therethrough and into the associated air bottle 1.. The other end of the plunger 42 is formed integrally as a valve closure member to co-operate with said valve seat- 40, and together comprise a pressureindicatingvalve and a spring 43 is fitted to urge said plunger 42 in a valve-opening direction.

The mouth-piece 44 of the breathing apparatus comprises ahollow rubber member to be fitted within the divers mouth and a substantially T-shaped member 45 extending therefrom, one branch of said T-shaped member: being connected to a flexible hose 46 adapted to passaround one side of the divers head to a demand valve (not illustrated) located adjacent the back of the divers-neck, and'the other branch of the T-shaped member being connected to another flexible hose 47 adapted to'pass. around the other side of the divers head to the exhaust valve secured to the demand valve.

The T-shaped member is provided with a small nozzle 48, having a jet-type orifice, and the orifice, is upwardly presented when the mouth-piece 44 is worn and is located substantially in line with the divers nose. The nozzle 48 is connected, by a separate hose 49, with the aforementioned passage 39 containing the valve in the boss 7'of the manifold.

The operation of the apparatus, when worn by a diver, is. as follows. The hand-knob 38 is rotated freely until the spring guide 34 abuts the skirted end 31 of the plunger 29, whereafter the spring load will react directly on the plunger. The spring load on the plunger 29 moves the piston 21 towards the annular shoulder 10, the tubular stem 22 on the piston 21 moving the tubular valve member 14 against its return'spring 18 so that the ch'amfered end thereof moves away from the resilient seating washer 16, thereby uncoveringthe holes 13 in the sleeve 12. The high pressure chamber 19 is connected to the air'bottles 1, 2 and hence air under pressure flows through the sleeve 12' and tubular stem 22 and thence through the. closure member 8 to the demand valve, whence it flows, on demand, to the diver.

The air under compression also passes between the tubular piston stem 22 and the sleeve 12 and reacts on the face of the annular piston 21, tending to move it,

against the force exerted by the pressure on the other side of the piston, towards the hand knob 38. The pressure also reacts on the effective area of the relief valve closure member 30 until, when said pressure attains a predetermined value, it moves the closure member 30 and plunger 29 against the main return spring 36, thepiston 21, incorporating the valve seat 23, moving withthe said member 30 and hence maintaining the relief valve closed. Movement of the tubular piston stem 22in this direction allows the inlet valve member 14 to close and cut off further supplies of compressed air to the demand valve until the pressure in said demand valve drops below said predetermined level.

If, e. g; the inlet valve 14 should leak so that the pressure in the demand valve exceeds said predetermined value, the piston 21 and closure member 30 will continue to move until the abutment 24 on said piston 21 contacts the stop 25 in the cylindrical member 3 when the relief valve closure member will be moved away from the valve seat 23 on the piston 21 to allow excess pressure to flow ed to atmosphere.

The apparatus is rendered inoperative by rotating the hand-knob 38in the opposite direction, when the force of themain return spring'36 will be taken off the plunger. 29 toallowthe inlet valve member 14 to seat and then allow'thei compressed air in. the system past theinlet 4. valve to blow-ofi to atmosphere. The light. spring. 33 fitted in compression between the control rod 32 and the plunger 29 is merely for the purpose of keeping the relief valve closure member 30 lightly seated when the apparatus is inoperative, and hence excluding dirt and moisture from the system;

The plunger 42 in the pressure indicating valve is normally depressed against its spring. 43 by the pressure in the associated bottle I, when the bottle 1 is charged, and thereby maintains said'valve closed. As soon as the pressure in the bottle falls below a predetermined value, the spring 43 moves the plunger 42 against said pressure to open the valve and allow compressed air from within the cylindrical member 3 to flow through a restricted orifice 50,v through said valve, through the hose 49 (Figures 2 and 3) to the nozzle 48 on the divers mouth-piece where it escapes through the jet into the water in the form of a stream of fine bubbles directly in front of the diverseyes. This acts as a signal to the diver that the air cylinders need replenishing.

The apparatus herein described is not confined to underwater apparatus but may, e. g. be used in contaminated atmospheres. device described to show that the cylinders 1 and 2 need re-charging should be replaced by an alternative device. For example, the air flowing through the pressure indicating valve, when the bottle pressure is low, could be used to move a small plunger adjacent the mouth-piece, 44 and thereby operate an indicating device immediately visible to the wearer of the apparatus. An advantage of this latter device is that no compressed air is lost thereby.

The control rod 32 need not necessarily be operated for axial movement by rotary movement of a hand-knob. For example, lever operated cam-means may be employed.

Having now described my inventionwhat I claim is:

1. Breathing apparatus comprising a gas bottle, a breathing connection, means connecting said bottle to said breathing connection, and an indicating means to indicate when said bottle needs replenishing and means acted on by the pressure in said bottle to hold said indi cating means in operative by pressure in said bottle above a minimum pressure and to operate said indicating means only when the pressure in said bottle falls below said minimum value, for indicating that the bottle requires replenishing.

2. Breathing apparatus according to claim 1 wherein said indicating means are visual.

3. Breathing apparatus according to claim 1 comprising a valve to be closed by gas pressure in said bottle and a spring biasing said valve to open when said pressure falls below a predetermined value to allow the passage of gas to operate said indicating means.

4. Breathing apparatus for underwater use according i to claim 3 wherein said valve communicates with the exterior of the apparatus and thereby releases a stream of bubbles when operated underwater.

5. Breathing apparatus according to claim 1 wherein control means are provided between said cylinder and said face piece, said control means comprising a manifold having an operating chamber, a pressure chamber, and an exhaust outlet, a hollow sleeve extending axially into said pressure chamber, a tubular valve member slidable on said sleeve, a piston located exterior of said pressure chamber having a hollow stem extending therefrom through said sleeve to engage said tubular valve member whereby movement of the piston in one direction moves said tubular valve member relative to said sleeve to uncover a plurality of holes in said sleeve and said stem to permit the passage of gas from said pressure chamber to said operating chamber, a plunger slidable to abut said piston, and spring means between said plunger and a movable abutment, and means to move said abutment whereby the spring loadon said plunger maybe varied.

In this case the visual indicating 6. Breathing apparatus according to claim 5 wherein References Cited in the file of this patent the piston and plunger co-operate to form a relief valve. UNITED STATES PATENTS 7. Breathing apparatus according to claim 6 wherein movement of the piston in the other direction is re- 2'362'643 Lambertsen 1944 stricted, whereby pressure in the operating chamber bears 6 on said plunger to open the relief valve. 

